The present invention relates to a pressure equalizing device for refrigerators. More particularly, this invention relates to a pressure equalizing device for refrigerators, which facilitates the opening of the doors of refrigerators.
Definitely, a refrigerator is an unmistakable achievement of science and technology. It is a cool result of the intensive research in thermodynamics, electric engineering, and material engineering such as heat pump, thermal expansion, latent heat, and the like.
One of the most well-known physical phenomena in cooling is the thermal contraction. When cooled down, the objects contract. It holds true to everything existent; solid, liquid, and even gas.
Refrigerator is a device to cool down the inside of a chamber that is thermally insulated from the outside. That means that everything in the chamber experiences thermal contraction. The air trapped in the chamber cannot be exceptional. It contracts under the cooling condition of the refrigerator.
When the door is open, the chamber gets filled with air from the outside, that is, warm air. If the door is closed and remains closed, the trapped air cools down and contracts. The cooled down and contracted air inside the chamber with a fixed volume brings about lower air pressure compared to that outside.
Then, the air pressure difference between the inside and outside of the chamber expresses itself as a force holding the door from opening.
The situation gets worse with the volume of air trapped in the chamber. Even with a refrigerator having a small volume of chamber, it happens when the temperature difference between the inside and outside of the chamber is very large.
A walk-in refrigerator is not uncommon in many industries. Considering the vast volume of chamber, the holding force of the door must be very demanding.
Accordingly, a need for a pressure equalizing device for refrigerators has been present for a long time considering the tendency of growing in size of refrigerator. This invention is directed to solve these problems and satisfy the long-felt need.